The former chief probation officer of San Mateo County pleaded not guilty Friday to two felony counts of possessing child pornography.

Stuart Forrest, 61, of San Mateo entered his plea a day after he was named in a complaint filed in Superior Court by prosecutors with state Attorney General Kamala Harris' office. He was released on $100,000 bail.

Forrest was placed on paid administrative leave Dec. 21 and retired 10 days later after serving three years as the county's chief probation officer.

He oversaw a department that evaluates and supervises adult and juvenile offenders and provides updates to courts on their progress. He joined the Probation Department in 1977.

The U.S. Postal Service and FBI had been investigating Forrest, which raised the possibility of federal charges. It was unclear what led to charges being filed in state court.

County prosecutors turned over the case to Harris' office. District Attorney Steve Wagstaffe said, "I felt that it was appropriate for the AG's office to prosecute the case in light of the close working relationship that my office has with the Probation Department."